This invention relates to a device for driving dot printing bars in a dot printer and more particularly, to a device for driving dot printing bars in a dot printer in which when a dot printing bar of bars selectively contact a friction roller which rotates continuously or intermittently, the bar or bars spring out to effect dot printing on a recording paper.
There have been proposed and practically employed a variety of devices for driving dot printing bars in dot printers and in one of the priorart dot print bar drive devices, flexible wires or bars are connected to the movable portions (movable iron pieces, for example) fo their respectively associated electromagnetic devices and one or more of the wires or bars spring out selectively as one or more of the movable iron pieces are attracted to an electromagnet or electromagnets to be caused to rock whereby the bar or bars effect dot printing on a recording paper.
Therefore, in such a prior art dot printing bar drive device, since it is necessary to space the movable iron piece from the pole portion of the associated electromagent by a distance corresponding to the protruding or spring-out distance of the wire or bar or convert the rocking movement of the movable iron piece as the iron piece is attracted to the electromagnet into the spring-out or protruding force of the wire or bar, the electromagneticdevice is required to be large in size or the time space which will elapse from the inputting of a selection command to the actual operation of the wire or bar is relatively longer as compared with the spring-out of protruding distance of the wire or bar which becomes an impediment in reducing the size of the bar drive device and/or accelerating the dot printing speed.